[a3_nm]

About the 2% figure: many things are insignificant in terms of climate change if you narrow down on them. Also, this 2% figure of the share of air travel is projected to increase, because the number of revenue passenger kilometers flown is quickly increasing (doubled in the last 10 years), cf https://ourworldindata.org/grapher/airline-capacity-and-traf....

And unfortunately carbon offsetting is rather unreliable (companies buying offsets don't have any incentive for the offsets to be actual savings). I'd be wary of climate change solutions that consist of continuing business as usual and assuming that decarbonation will happen in some other sectors. I also suspect the 20% price increase estimate works for a specific price of carbon, but that price could increase if carbon offsets started becoming widely used (and the demand increases).

Anyway, I don't know what's the right way for the US to reduce travel emissions, whether that's electric coaches, cheaper rail, taxation to increase prices and reduce demand... But I don't think the solution can be "just keep planes and add carbon capture".